Calking gun



s. cREWE CALKING GUN A Jan.. 28,` 1941' Filed Sept. l', 1959 INVENTOR I SAMUEL CREWE Patented Jan. 28, 1941 UNITED STATES PATENT OFFiCE CALKING GUN Application September 1, 1939, Serial N o. 293,023

4 Claims.

This invention relates to improvements in a gun for feeding semi-solid material under pressure, such as a calking gun.

An object of the present invention is to provide novel means for releasing the feed bar. which holds the material under pressure so that the feed bar may be retracted when it is necessary to reload the gun.

Another object of the present invention is to provide means for releasing the feed bar when the operator ceases to actuate the gun so as to relieve the pressure on the material in the gun and to prevent dripping or continued extrusion 1 of material from the nozzle of the gun when `5 the gun is not being actively used to apply the material.

Other advantages of the invention will appear in the accompanying description and drawing and the essential features thereof will be set forth in the claims.

In the drawing, Fig. l is a central longitudinal sectional View through a gun embodying my inn vention and showing the operating handle in released position; Fig. 2 is an enlarged sectional View of a portion of Fig. 1 and showing the parts when the operating handle is in fully actuated position; Fig. 3 is a view similar to Fig. 2 but showing the handle partially returned toward unoperated position; while Fig. 4 is a transverse sectional view taken along the line 4-4 of Fig. 2.

While my invention may be applied to various types of gun, I have chosen to illustrate the same combined with a portable calking gun such as is fully disclosed and claimed in Patent No. 1,976,253 granted October 9, 1934 to Samuel Clark. This gun comprises a cylindrical material reservoir I which is closed at one end by the cap I I provided with an opening Ila through which projects the feed bar. The other end is closed by a conical shaped cap I2 which terminates in a feed nozzle I3. For pushing the material out of the gun a piston I4 fits within the cylinder It and is actuated by a piston rod or feed bar I5 extending rearwardly. This bar is provided with a series of notches or teeth ISa in its upper edge by means of which the bar is driven forward to place the calking material under pressure.

The driving means for bar I5 comprises a pawl I5 having teeth on its lower edge adapted to engage the teeth a. A spring I'I normally urges the pawl into engagement with the feed bar. A pin and slot connection I8 connects the pawl with the operating handle I9.. This handle is 55 channel shape in section with its web toward the front and parallel flanges extending rearwardly. The pin I 8a of the pin and slot connection is carried in the flanges of the handle I9. This handle in turn is pivotally mounted at 2i)V on a casing 2l which houses the operating mechanism at the rear o f the gun. Rigid with this casing portion is a pistol grip 22 which is generally channel shape in form with its web toward the rear and parallel side flanges extending forwardly. A spring 23 normally biases the handle I9 to its forwardmost or unoperated position. A detent 24 is mounted for vertical sliding movement in the'rear portion of casing 2I and is urged toward engagement with the teeth Ia by a spring 25.

Means is provided for lifting pawl I6 and detent 24 out of engagement with the feed bar I5 to permit this bar to be pulled rearwardly by means of handle I5b when it is-desired to reload the gun. This releasing means for the' feed bar also acts to move the pawl It and the detent 24 out of engagement with the feed barwhen the handle i9 is in its forwardmost or inoperative position as shown in Fig. 1 so that pressure is relieved on the materialin the gun ahead of piston Il allowing retrograde movement of this piston if necessary so that material does not dribble from the end of nozzley I3 when it is not desired.

This release means for the pawl and detent is operated automatically by movement of the handle I9 from the position of Fig. 2 to that of Fig. 1. Mounted on the forward side of one of the flanges lof handle I9 is a projection 2E which engages a pin 2l on pawl I6 when handle I9 moves in a clockwise direction from the position of Fig. 2 towardrthe position of Fig. l. The projection 26 is arranged to engage the pin 21 only after pawlY I6 has been moved several teeth toward the rear by clockwise movement of handle I9. For instance the pawl I6 will be lifted entirely out of engagement with the teeth I5a, on

l slight additional movement of handle I3 clockwise from the position of Fig. 3, and it is obvious that if the handle I9 is moved from the position of Fig. 3 in a counterclockwise direction to the position of Fig. 2, the feed bar I5 will be driven forward. This permits driving of the feed bar forward while pressure is maintained by detent 24. f

Additional movement of handle I9 in a clockwise direction from the position of Fig. 3 to that of Fig. 1 also causes release of the detent 24. The mechanism for this purpose comprises a pin 28 loosely held in an opening in detent 24 by the enlarged head 28a. An intermediate portion of this pin rests upon a pin or rivet 29 secured in casing 2I. A projection 30 extends toward the rear from one or both of the flanges of the handle I9 and carries a pin 3I or other projection similarly located and adapted to engage the forward end of pin 28 during the last increment of clockwise movement of handle I9 as it moves to the position o-f Fig. 1. Thus only when the operator has fully released handle I9 to cease operation of the gun or to lay it down does the projection 3| lift the detent 24 out of engagement with the teeth Ia.

It is believed the operation of the gun will now be clear from the foregoing description but a brief rsum is given for purposes of clarity. With the parts in the position of Fig. 1 and with the material in the gun ahead of the piston I4 the operator grasps the pistol grip 22 and moves the handle I9 toward the rear or in a counterclockwise direction. The first portion of this movement causes projection 26 to move away from the pin 21 permitting pawl I6 to engage the teeth I5a on the feed bar impelled by the spring I'I. Further movement of handle I9 in a counterclockwise direction drives the feed bar and piston I4 forward to extrude material from the nozzle I3. Repeated operations of this sort moving handle I9 from the position `of Fig. 3 to the position of Fig. 2 and back again will drive the feed bar continuously forward under pressure which is retained by the detent 24. When the operator ceases to use the gun and completely releases the handle I9 it is returned to the position of Fig. 1 by spring 23, whereupon the projection 26 engages pin 21 to lift pawl I6 clear of teeth I5a and the projection 3| engages the forward end of pin 28 and lifts the detent 24 out of engagement with teeth Ia. Any pressure stored in the gun ahead of piston I4 will then cause a slight backward movement of the piston and feed bar to relieve this pressure. The forward travel of feed bar I5 is limited by a pin 32 which indicates that the gun needs refilling. This is easily done when handle I9 is in the position of Fig. 1 because the feed bar is then free to be moved rearwardly by handle I5b and by unscrewing the conical cap I2 the gun may be recharged.

What I claim is:

1. In a gun having piston means for discharging material under pressure and a feed bar for said piston, a pawl engageable with said bar to drive it in discharging direction, a detent normally engaging said bar to prevent its movement in an opposite direction, operating means for said pawl oscillatable in material-discharging and in return directions, means on said operating means for engaging said pawl to move it away from said bar, and there being an operative connection between said operating means and said detent for raising said detent out of engagement with said bar by movement of said operating means in return direction.

2. In a gun having piston means for discharging material under pressure and a feed bar for said piston, a pawl engageable with said bar to drive it in discharging direction, a detent normally engaging said bar to prevent its movement in an opposite direction, operating means for said pawl comprising a handle oscillatable between an unoperated and a fully-operated position, means urging said handle to unoperated position, an operative connection between said handle and said pawl to move the latter in material discharging direction as said handle moves toward operated position, an abutment on said handle adapted to lift said pawl out of engagement with said bar by movement of said handle toward unoperated position, and an Operative connection between said handle and detent for moving the latter out of engagement with said Ear as said handle moves to unoperated posiion.

3. In a gun having piston means for discharging material under pressure and a feed bar for said piston, a pawl engageable with said bar to drive it in discharging direction, a detent normally engaging said bar to prevent its movement in an opposite direction, operating means for said pawl comprising a handle oscillatable between an unoperated and a fully-operated position, means urging said handle to unoperated position, an operative connection between said handle and said pawl to move the latter in material discharging direction as said handle moves toward operated position, a lever for lifting said detent out of engagement with said bar, and an abutment on said handle adapted to move said lever in detent-lifting direction as said handle moves to unoperated position.

4. In a gun having piston means for discharging material under pressure and a feed bar for said piston, a pawl engageable with said bar to drive it in discharging direction, a detent normally engaging said bar to prevent its movement in an opposite direction, operating means for said pawl comprising a handle oscillatable between an unoperated and a fully-operated position, means urging said handle to unoperated position, an operative connection between said handle and said pawl to move the latter in material discharging direction as said handle moves toward operated position, an abutment on said handle adapted to lift said pawl out of engagement with said bar by movement of said handle toward unoperated position, a lever for lifting said detent out of engagement with said bar, and an abutment on said handle adapted to move said lever in detent-lifting direction as said handle moves to unoperated position, said first named abutment being arranged to lift said pawl before said second named abutment causes lifting of said detent.

SAMUEL CREWE. 

